SELinux: memory leak in security_context_to_sid_core

Fix a bug and a philosophical decision about who handles errors.

security_context_to_sid_core() was leaking a context in the common case.
This was causing problems on fedora systems which recently have started
making extensive use of this function.

In discussion it was decided that if string_to_context_struct() had an
error it was its own responsibility to clean up any mess it created
along the way.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index b52f923..d11a815 100644 (file)
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -811,11 +811,12 @@ static int string_to_context_struct(struct policydb *pol,
        /* Check the validity of the new context. */
        if (!policydb_context_isvalid(pol, ctx)) {
                rc = -EINVAL;
-               context_destroy(ctx);
                goto out;
        }
        rc = 0;
 out:
+       if (rc)
+               context_destroy(ctx);
        return rc;
 }
 
@@ -868,8 +869,7 @@ static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
        } else if (rc)
                goto out;
        rc = sidtab_context_to_sid(&sidtab, &context, sid);
-       if (rc)
-               context_destroy(&context);
+       context_destroy(&context);
 out:
        read_unlock(&policy_rwlock);
        kfree(scontext2);